I. Field of the Invention:
This invention relates generally to surgical apparatus, and more particularly to an introducer to be used in accurately locating the injection site when treating female urinary stress incontinence by augmenting the tissue proximate the urinary sphincter with injectable materials.
II. Discussion of the Prior Art
In treating stress incontinence, especially in female patients, it has been found expedient to augment the tissue surrounding the urinary sphincter with injectable materials. In this regard, reference is made to the Ersek et al. U.S. Pat. No. 5,336,263, whose content is hereby incorporated by reference. As is explained therein, by injecting a mixture of solid micron-sized particles and a suitable fluid carrier intrauretherally so as to deposit the particles at the site of the urinary sphincter, the ability of the sphincter to cut-off urine flow during stress episodes, such as coughing, sneezing, laughing, etc., is enhanced.
In my published U.K. patent application 2,284,158A, I describe an instrument which I have termed an "injection catheter", that facilitates injection of substances for augmenting the tissue surrounding the bladder neck. That instrument comprises an outer tubular sheath having a proximal end, a closed distal end and a lumen extending therebetween. Formed a predetermined distance proximal to the closed distal end of the sheath is an aperture into which urine may flow when the catheter is inserted into the patient's urethra and advanced until the aperture passes beyond the bladder neck into the urinary bladder itself. A plurality of flexible injection needles are affixed to a common hub and the outer sheath includes a corresponding plurality of exit holes. When the needles are advanced through the lumen of the sheath to exit the openings in the sheath wall provided for them, an injectant can be delivered under pressure through the hub and simultaneously through the injection needles into the tissue to be augmented. The apertures on the sheath provide a reference for locating the distance that the sheath must be retracted so that the aperture through which the urine passes is at the bladder neck.
In using the device described in the aforereferenced U.K. patent application, the needles are made to penetrate through the urethral wall into the surrounding tissue to be augmented. I have found it preferable to intrauretherally inject tile augmenting substance and it is the principal object of the present invention to provide an instrument for accurately locating the entry point on the patient's body where the needle of an injection syringe penetrates so that a fluid suspension of injectable material may be accurately placed into the surrounding tissue at a location for augmenting the tissue proximate the urinary bladder neck or mid-uretherally, if appropriate.